1. Field
Example embodiments relate to a method of forming a conductive structure in a semiconductor device and a method of manufacturing a semiconductor device having the conductive structure. More particularly, example embodiments relate to a method of forming a conductive structure including metal and a method of manufacturing a semiconductor device using the method of forming the conductive structure.
2. Description of the Related Art
Recently, semiconductor devices have been developed to have high packing density, high working frequency, low operation voltage, etc. Thus, sizes of patterns formed on a chip have been considerably reduced and distances between the patterns have also been greatly reduced.
Polysilicon may be used to form a gate electrode of a conventional semiconductor device or a conductive pattern for electrically connecting elements in the semiconductor device. However, resistance of the polysilicon may increase as the degree of integration of the semiconductor device increases.
Considering the above-mentioned problem, a conventional conductive pattern or a gate electrode in the semiconductor device may include polysilicon and a metal silicide to reduce resistance of a resultant structure, e.g., as compared to a structure including only polysilicon, and have electrical characteristics substantially similar to those of polysilicon. However, such a structure, i.e., a conductive pattern or gate electrode, may not reduce resistance to a sufficient level required by a highly integrated semiconductor device. As a result, a semiconductor device has been developed to include a conductive pattern or a gate electrode having metal, so that resistance of the structure may be lower than the resistance of the structure including polysilicon and metal silicide.
When the conductive pattern or the gate electrode includes metal, however, the conductive pattern or the gate electrode may be easily oxidized in semiconductor manufacturing processes performed after forming the conductive pattern or the gate electrode on a substrate. Hence, the metal conductive pattern or gate electrode formed via conventional methods may not have a desired low resistance after forming the semiconductor device. For example, when metal included in the conductive pattern or the gate electrode is oxidized, the conductive pattern or the gate electrode may have a reduced width, thereby increasing the resistance thereof. Additionally, electrical failures of the semiconductor device may be generated since a bridge caused by metal oxide in the conductive pattern or the gate electrode may be formed between adjacent conductive patterns, adjacent gate electrodes, or the conductive pattern and the gate electrode.
Further, resistance of the conventional metal conductive pattern or gate electrode may increase even further when the conductive pattern or the gate electrode is nitrified or nitrogen is permeated into the conductive pattern or the gate electrode. Furthermore, the conventional metal conductive pattern or gate electrode may have a deformed structure, e.g., may be inclined at a predetermined angle, due to stress caused by nitrogen.
To solve the above-mentioned problems related to the conductive pattern or the gate electrode including metal, a novel method of forming a conductive structure in a semiconductor device without increasing the resistance of the conductive structure and electrical failures of the semiconductor device while ensuring a desired shape of the conductive structure is required.